The concept of projection headlights was first proposed by Mercedes in 2018 as Digital Light, which can project a lot of information such as navigation, weather, traffic warnings, pedestrian crossings, etc.

Later, HiPhi X and IM L7 adopted the projection headlights' technology in 2020 and 2021 respectively.

However, this technology was often considered flashy and not cost-effective until its adoption by Huawei's AITO M9, which then gained widespread recognition.

Recently, Porsche has also joined this trend, with the newly released Cayenne featuring projection headlights' functionality.

Technical Implementation of Projection Headlights

Projection headlights can be implemented mainly in two ways: MicroLED and DLP solutions.

MicroLED solution

It controls the pixel by switching the matrix of the LED surface light source on and off. The LED has an integrated switch control MOSFET and control chips embedded around the LED to achieve an integrated design of the light source. Currently, the primary light sources are Nichia's with 16,000+ pixels and Osram's with 25,600+ pixels.

DLP solution

DLP (Digital Light Processing) is based on the digital micromirror device ( DMD) developed by Texas Instruments (TI) of the United States. The DLP projection technology applies a digital micromirror chip (DMD) as the main key processing component to achieve digital optical processing.

Comparison of MicroLED and DLP solutions

	Pixels	Power Consumption	Cost
DLP	900,000~1,300,000	High	High
MicroLED	16,000~25,000	Low	Low

The cost of DLP mainly lies in the DMD, with a 1,000,000-pixel DMD costing about 1,000 RMB according to TI's official website;

AITO M9 adopts the DLP projection solution. However, its power consumption is very high, close to 70W.

DLP Projection Headlights Electronic System

The electronic system of DLP usually uses a complete solution provided by TI, which includes the controller DLPC×××, DMD components DLP×××, and the power management chip TPS99001-Q1.

Inputs include control information from the body domain and ADAS domain on the vehicle side, as well as projection video stream information from the entertainment domain. The DLPC chip transmits video signals through Sub LVDS video lines to control the DMD chip to project the corresponding video stream.

Case Study: Huawei AITO M9 Projection Headlights' Technology

The innermost projection module has 1,300,000 pixels.

Ultra-near-field and ultra-high definition projection

Using a single-headlight with 1,300,000 pixels, Huawei boasts of its clarity (MTF<0.4) and ultra-near-field projection within 3m. Projection Headlights can achieve this. The introduction mentions using a dual-reflective optical structure to achieve this.

Dual-lamp fusion technology

It can be understood that the pattern projected onto the ground is stitched together by projection patterns from both sides, achieving higher brightness and contrast. This requires strong algorithm correction capabilities to avoid ghosting issues.